The present invention relates generally to electronic systems for remotely controlling and for remotely monitoring a plurality of electrical apparatuses, and which provides for internet-based two-way communication, monitoring and control. More particularly, the present invention relates to such systems that are scalable to permit many additional apparatuses to be easily added to the existing system at a remote site, in which the newly added apparatuses automatically register upon the system during periodic registration subroutines and in which the real-time clocks of the system components are periodically corrected to the current Greenwich Mean Time by a time synchronization subroutine.
A prior monitoring and control system is shown in U.S. Pat. No. 6,236,332, which is assigned to the assignee of this invention. This system provides for two-way signaling, but does not contemplate control of a plurality of devices by the remote unit. Neither does this patent provide for automatic registration of system components or for automatic time synchronization among the system components.
Another known system for remotely controlling electrical apparatus is shown and described in U.S. Pat. No. 5,936,362, which is also assigned to the assignee of this invention. The system disclosed in this patent has wide application to a variety of different remotely located apparatus, including the lighting of signs, climate control, irrigation control, traffic control and so forth. However, this system operates through the one-way wireless transmission of radio signals from the host computer. Thus, the remote site is generally limited to a location within the range of reliable radio signaling. Electronic signaling equipment must generally be replicated at each site where the remotely controlled apparatus is located.
Yet another system is disclosed in U.S. Pat. No. 5,898,384, which is also assigned to the assignee of this invention. As taught in the preferred embodiment, this patent teaches the use of radio frequency (RF) pagers to remotely activate or deactivate electrical apparatus, with one pager required for each remote device. This system is also a one-way wireless transmission of radio signals
A need exists for a system for remotely controlling and monitoring apparatus in which many additional devices may be easily and inexpensively added to the system without having to replicate the entire remote portion of the system at each remote site for each additionally added device.
A need also exists for automatically registering each system component on the control and monitoring system so that a network operating center can quickly communicate with existing and newly installed devices.